Led lighting that has continuous and adjustable color temperature (ct), while maintaining a high cri

ABSTRACT

A modular, standalone, and multi-functional electronic and mechanical platform for light-emitting diode (LED) lighting applications that has continuous and adjustable color temperature (CT) is provided. In particular, a modular LED device is utilized as a standalone lighting device or, alternatively, as a universal and generic building block for forming lighting devices for lighting application. The modular LED device includes an LED circuit, a digital signal processor (DSP), a network interface, and a power supply that can be packaged in a compact, thermally controlled housing. Additionally, the housing can provide alignment and fastening mechanisms for easily coupling one modular LED device to another modular LED device.

FIELD OF THE INVENTION

The present invention generally relates to the field of illuminationdevices formed of light-emitting diodes. In particular, the presentinvention is directed to a modular, standalone, and multi-functionalelectronic and mechanical platform for light-emitting diode (LED)lighting applications that has continuous and adjustable colortemperature (CT) and can maintain a high CRI.

BACKGROUND

An LED is a semiconductor device that can produce an emission with abrilliant color and high efficiency in spite of its small size. In thepast, LEDs have been applied mainly to display devices. For that reason,the use of LEDs as a light source for illumination purposes has not yetbeen researched and developed sufficiently.

In order to break into the lighting market, it is beneficial to presentthe market an illumination product that provides compelling motivationfor use thereof. In particular, today's LED solutions in the lightingmarket are very application-specific and/or excessively cumbersome,i.e., too complex mechanically and technically, to compel their generaluse.

For example, in a typical LED solution, the LEDs therein dictate one ormore printed circuit board designs and then the printed circuit boarddesigns dictate the mechanical design. The resulting product is,therefore, limited because its design is suited for one applicationonly, such as for a desk lamp or a ceiling light only. Its designspecifications are not suitable for other lighting applications.Alternatively, a generic LED lighting product may be provided that isformed of separate components that require assembly, such as separateelectronics, separate power supplies, separate cabling, and a separatecontrol system. Consequently, such a generic design is difficult to sellto a customer because it requires a highly technical understandingthereof, which is overwhelming to the customer. Because it is notunderstood easily by a non-technical individual (e.g., customer), thisgeneric LED lighting product is not likely to become a standard in theillumination market. For these reasons, a need exists for a generic LEDlighting product that provides ease of use for a non-technicalindividual and that is multi-functional, in order to provide a LEDlighting product that is accepted readily into the lighting market andthat is suitable for multiple lighting applications.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a chromaticity diagram;

FIG. 2A illustrates a schematic diagram of a multiple-in-1 (MIO) LED(3-in-1) device in accordance with an embodiment of the invention;

FIG. 2B illustrates a top view of the MIO-LED (3-in-1) device asdepicted in FIG. 2A;

FIG. 2C illustrates a cross-sectional view of the MIO-LED (3-in-1)device as depicted in FIG. 2A;

FIG. 3A illustrates a schematic diagram of a MIO-LED (4-in-1) device ofanother embodiment of the invention.

FIG. 3B illustrates a top view of the MIO-LED (4-in-1) device of asdepicted in FIG. 3A; and

FIG. 3C illustrates a cross-sectional view of the MIO-LED (4-in-1)device as depicted in FIG. 3A;

FIG. 4 illustrates a functional block diagram of an LED module system,in accordance with the invention;

FIG. 5 illustrates a perspective front view of a modular LED device,which houses the LED module system of FIG. 4;

FIG. 6 illustrates a perspective back view of the modular LED device,which houses the LED module system of the present invention;

FIGS. 7A and 7B illustrate a first and second perspective view,respectively, of a PCB assembly for forming the LED module system of thepresent invention;

FIG. 8 illustrates an exploded view of modular LED device, which housesthe LED module system of the present invention;

FIG. 9 illustrates a cross-sectional view of modular LED device, whichhouses the LED module system of the present invention;

FIG. 10 illustrates a front view of a housing/heatsink of the modularLED device that houses the LED module system of the present invention;

FIG. 11 illustrates an exemplary LED configuration of the LED modulesystem of the present invention;

FIG. 12 illustrates a flow diagram of a method of operating the LEDmodule system of the present invention; and

FIG. 13 illustrates an LED circuit for increased efficiency.

FIG. 14 illustrates a configuration of the modular LED device where asecondary coupler provides power thereto via induction.

FIG. 15 shows a configuration where a DC power source provides power toan external primary coupler.

FIG. 17 shows an inductive power supplier; 2010 may incorporateadditional circuitry configured to detect the position of the lightsource in a string.

FIG. 18 shows a common rail that supplies high frequency power directlyto a primary coupler.

FIG. 19 shows a common rail that supplies mains power (AC) or DC powerindirectly to a primary coupler.

SUMMARY OF SOME EMBODIMENTS OF INVENTION

One embodiment of the present invention is a Light Emitting Diode, LED,module lighting system (100) comprising:

-   -   two or more multiple-in-one, MIO, LED devices (120), each        MIO-LED device (120) comprising at least three LEDs (212, 214,        216, 312, 314, 316, 318) together in a housing body (210, 310)        wherein:        -   a) the light emitting parts of said at least three LEDs are            encapsulated in and connected by a solid, transparent            material, and        -   b) said at least three LEDs (212, 214, 216, 312, 314, 316,            318) each emit a different colour of light, whereby each            colour is selected from the group consisting of blue, red,            green yellow, orange, cyan, purple, white and magenta,    -   a digital signal processor, DSP (112), and    -   a digital to analogue converter, DAC, (124) for each LED (212,        214, 216, 312, 314, 316, 318) or a set of LEDs, wherein the        system is configured so that signals from the DSP (112) regulate        the overall colour and brightness of light emitted by the        MIO-LED devices (120) by controlling the power applied to each        LED (212, 214, 216, 312, 314, 316, 318) or set of LEDs through        the DAC.

Another embodiment of the present invention is an LED module system(100) as described above, wherein the solid, transparent materialcomprises at least one phosphor material (228) that is activated bylight emitted from one or more of said LEDs, so producing light having aspectrum broader than that emitted by said activating LED.

Another embodiment of the present invention is an LED module system(100) as described above, wherein the phosphor material (228) comprisesone or more of the phosphors listed in Tables 1, 2 or 3, or an opticalbrighteners.

Another embodiment of the present invention is an LED module system(100) as described above, wherein:

-   at least one LED in a MIO-LED (120) device emits blue light, and-   phosphor material (228) is yttrium-aluminum-garnet, YAG, phosphor.

Another embodiment of the present invention is an LED module system(100) as described above, wherein said DSP (112) is configured tocontrol the power applied to each LED (212, 214, 216, 312, 314, 316,318) or set of LEDs, such that the colour and brightness of lightemitted is the same for each MIO-LED device (120).

Another embodiment of the present invention is an LED module system(100) as described above, further comprising a pulse width modulator,PWM, switch (126) for controlling the power applied to each LED (212,214, 216, 312, 314, 316, 318) or a set of LEDs, using signals from theDSP (112).

Another embodiment of the present invention is an LED module system(100) as described above, wherein the DSP is configured to control thePWM switch (126) to adjust the power supplied to two or more LEDs of thesame colour present in separate MIO-LED devices (120), when said two ormore LEDs emit different shades of said colour.

Another embodiment of the present invention is an LED module system(100) as described above, wherein the DSP is configured to control theDAC to adjust the power supplied to two or more LEDs of the same colourpresent in separate MIO-LED devices (120), when said two or more LEDsemit different shades of said colour.

Another embodiment of the present invention is an LED module system(100) as described above, wherein said two or more LEDs of the samecolour have not been grouped by binning.

Another embodiment of the present invention is an LED module system(100) as described above, further comprising one or more temperaturesensors (130) configured to provide temperature information of themodule to the DSP (112).

Another embodiment of the present invention is an LED module system(100) as described above, wherein the DSP (112) is configured to controlof the power applied to each LED (212, 214, 216, 312, 314, 316, 318) orset of LEDs of an MIO-LED device (120) based on temperature informationreceived from the temperature sensors (130), such that the colour andbrightness of light emitted from each MIO-LED device (120) is maintainedwhere there are changes in temperature.

Another embodiment of the present invention is an LED module system(100) as described above, further comprising one or more air cooling fan(260), configured to cool at least some of the LEDs (212, 214, 216, 312,314, 316, 318).

Another embodiment of the present invention is an LED module system(100) as described above, wherein said DSP (112) is configured tocontrol power to the fan (260) based on temperature information receivedfrom the temperature sensors (130). Another embodiment of the presentinvention is an LED module system (100) as described above, wherein theDSP (112) is configured, such that the colour and brightness of lightemitted from each MIO-LED device (120) is maintained where there arechanges in temperature.

Another embodiment of the present invention is an LED module system(100) as described above, further comprising one or more networkinterfaces (114) configured to signals to the DSP (112), allowing anexternal control.

Another embodiment of the present invention is an LED module system(100) as described above, further comprising one or more IR sensors(114) configured provide to signals to the DSP (112), allowing anexternal control.

Another embodiment of the present invention is an LED module system(100) as described above, further comprising a power supply (116)configured to supply power to the LEDs (212, 214, 216, 312, 314, 316,318) and other components.

Another embodiment of the present invention is an LED module system(100) as described above, wherein said power supply (116) has aplurality of DC voltage outputs, each providing a different voltage tomatch the rating voltage for a colour-emitting LED (212,214, 216,312,314, 316, 318).

Another embodiment of the present invention is an LED module system(100) as described above, wherein said power supply (116) is configuredto adapt it's output level, for at least one colour dependent, on therequired light output, controlled by the DSP.

Another embodiment of the present invention is an LED module system(100) as described above, further comprising a secondary inductioncoupler (2005), which provides power to the power supply (116) byelectromagnetic induction from a primary induction coupler (2006).

Another embodiment of the present invention is an LED module system(100) as described above, further comprising a memory storage device(128) configured to provide data to the DSP (112) regarding colourand/or brightness compensation information of each MIO-LED device (120).

Another embodiment of the present invention is an LED module system(100) as described above, wherein the DSP (112) is configured tocontinuously monitor the power supplied to each LED (212, 214, 216) inorder to maintain the colour and brightness provided by each MIO-LEDdevice (120).

Another embodiment of the present invention is an LED module system(100) as described above, wherein the colour and brightness aremaintained according to relationships between current and colourbehavior, and/or light output vs. temperature data.

Another embodiment of the present invention is an LED module system(100) as described above, wherein said relationships are stored as datawithin storage device (128) where present.

Another embodiment of the present invention is an LED module system(100) as described above, wherein the colour temperature, CT, of theemitted light is adjustable.

Another embodiment of the present invention is an LED module system(100) as described above, capable of emitting light that provides a highcolour rendition index, CRI.

Another embodiment of the present invention is a modular LED device(201) comprising a housing and one or more LED module systems (100) asdescribed above, whereby:

-   -   an array of MIO-LED devices (120) is arranged as a light        emitting surface    -   a mechanical means to stack two or more modular LED devices        (201) is provided.

Another embodiment of the present invention is a modular LED device(201) as described above, whereby said mechanical stacking means alignsthe respective light emitting surfaces to project light towards the samedirection.

Another embodiment of the present invention is a modular LED device(201) as described above, wherein the housing comprises an interfacingmaterial which can be used to make contact with other heat conductivematerials, so as to transfer heat from the device more easily.

DETAILED DESCRIPTION OF THE INVENTION

Unless defined otherwise, all technical and scientific terms Used hereinhave the same meaning as is commonly understood by one of skill in theart. All publications referenced herein are incorporated by referencethereto. All United States patents and patent applications referencedherein are incorporated by reference herein in their entirety includingthe drawings.

The articles “a” and “an” are used herein to refer to one or to morethan one, i.e. to at least one of the grammatical object of the article.By way of example, “a cooling fan” means one cooling fan or more thanone cooling fan.

Throughout this application, the term “about” is used to indicate that avalue includes the standard deviation of error for the device or methodbeing employed to determine the value.

The recitation of numerical ranges by endpoints includes all integernumbers and, where appropriate, fractions subsumed within that range(e.g. 1 to 5 can include 1, 2, 3, 4 when referring to, for example, anumber of cooling fans, and can also include 1.5, 2, 2.75 and 3.80, whenreferring to, for example, measurements). The recitation of end pointsalso includes the end point values themselves (e.g. from 1.0 to 5.0includes both 1.0 and 5.0)

The present invention relates to a generic LED lighting product thatprovides ease of use for a non-technical individual and that ismulti-functional and suitable for multiple lighting applications. Inparticular, a modular LED device of the present invention may beutilized as a standalone lighting device. Alternatively, the modular LEDdevice of the present invention may be utilized as a universal andgeneric building block for forming lighting devices for any lightingapplication. In particular, a lighting device may be formed of an easilyconfigured arrangement of multiple modular LED devices of the presentinvention.

Reference is made in the description below to the drawings whichexemplify particular embodiments of the invention; they are not at allintended to be limiting. The skilled person may adapt the device andsubstituent components and features according to the common practices ofthe person skilled in the art.

FIG. 4 illustrates a functional block diagram of an LED module system100, in accordance with the invention. LED module system 100 is theelectrical design of a modular LED device that provides a genericbuilding block that is easy to use and suitable for multiple lightingapplications. LED module system 100 preferably includes an LED circuit110, a digital signal processor (DSP) 112, a network interface 114, anda power supply 116. LED circuit 110 further includes an LED array 118that is formed of a plurality of “multiple-in-one”-LED (MIO-LED) devices120 (e.g., MIO-LED devices 120-1 to 120-n), a plurality of currentsources 122 (e.g., current sources 122-1 to 122-n), at least onedigital-to-analog converter (DAC) 124, a plurality of pulse-widthmodulation (PWM) switches 126 (e.g., PWM switches 126-1 to 126-n), atleast one storage device 128, one or more temperature sensors 130, andan infrared (IR) sensor 132. A suggested configuration connecting thecomponents of LED module system 100 is shown in FIG. 4.

LED array 118 of LED circuit 110 may be any array configuration of LEDdevices, such as an array of MIO-LED devices 120. Example LEDconfigurations include, but are not limited to, 15×3, 16×4, 17×4, 17×5,and 18×5 arrays.

Multiple-In-One-LED Device (MIO-LED Devices)

Each MIO-LED device 120 (e.g., each MIO-LED device 120-1 through 120-n)of LED array 118 may comprise a multitude of LEDs i.e. it may be a‘multiple-in-one’ LED-device (MIO-LED). A MIO-LED device, is a devicehaving a number of LEDs in one housing body e.g. 3 LEDs (3-in-1), 4 LEDs(4-in-1), 5 LEDs (5-in-1), 6 LEDs (6-in-1), 7 or more LEDs etc. Of theLEDs present in a MIO-LED device, any three of them each may emit adifferent colour of light, whereby each colour is selected from thegroup consisting of blue, red, green yellow, orange, cyan, purple, whiteand magenta,

The LEDs used in the present invention can be any kind of LED known inthe art, capable of providing light at the required wavelength or withina defined band of wavelengths. LEDs typically comprise semiconductingmaterial impregnated, or doped, with impurities to create a p-njunction. Such LEDs behave like diodes insofar as current flows from thep-side, or anode, to the n-side, or cathode, but not in the otherdirection. The wavelength of light emitted, depends on the band gapenergy of the materials forming the p-n junction. Where thesemiconducting material is an inorganic substance or mixture, it can beany suitable for the wavelength required e.g. aluminum gallium phosphide(AlGaP) for green light or gallium phosphide (GaP) for red, yellow orgreen light, zinc selenide (ZnSe) for blue light. Such combination ofsemiconducting materials are known in the art. Where the semiconductingmaterial is an organic substance or mixture (i.e. producing an OLED), itcan be any suitable for the wavelength required. Such organic substancesare known in the art. The term LED used herein covers light emittingsemiconductors which are formed of inorganic or organic materials.

Generally, the quality of white light produced by light sources forillumination purposes is expressed in terms of a colour rendition index(CRI) value. More specifically, light sources, such as LEDs, of the samecolor can vary widely in the quality of light that is emitted. One lightsource may have a continuous spectrum, while the other light sourceemits light in a few narrow bands only of the spectrum. Therefore, auseful way to determine the quality of a light source is its CRI, whichserves as a quality distinction between light sources emitting light ofthe same color. The highest CRI attainable is 100. CRI is a method ofdescribing the effect of a light source on the color appearance ofobjects, compared with a reference light source of the same colortemperature. Additionally, CT is a simplified way to characterize thespectral properties of a light source. Low CT implies warmer (moreyellow/red) light, while high CT implies a colder (more blue) light. Thestandard unit for color temperature is Kelvin (K). For example, daylighthas a rather low CT near dawn (approximately 3200K) and a higher CTaround noon (approximately 5500K). With this in mind, the use of theMIO-LED devices 120 in an LED array 118 provides a LED module system 100and associated modular LED devices (FIGS. 5 through 10) with acontinuous, uniform, and adjustable CT range (e.g., 3200 K to 9500 K)while maintaining a high CRI (e.g., 90 or greater) for lightingapplications.

The MIO-LED device has high CRI values for lighting applications, suchas, for example, overhead lighting in a room or outdoor area lighting.Because a light source emits radiant energy that is relatively balancedin all visible wavelengths will appear white to the eye, the LED devicesof the present invention provide multiple LEDs e.g., red, green andblue, in one package, which allows color mixing in order to provide anappropriate white light source for illumination purposes that,additionally, has the ability to provide CT tracking.

In particular, the MIO-LED devices of the present invention may utilizeat least one phosphor material for converting coloured light (e.g. red,green blue) into broader spectrum light, such as, for example, whitelight. A phosphor material is any material that is activated by light(e.g. blue, ultraviolet, red, green) produced by an LED, so producingbroader spectrum light, such as, for example, white light. Broaderspectrum light, is light which has a wider bandwidth compared with theactivating light i.e. the LED. Preferably a blue LED is provided incombination with phosphor material for producing white light.

The phosphor material may be disposed over the other LEDs of the MIO-LEDdevice; in doing so, it provides a mechanism for diffusing the lightemitted by the LED, which renders the LED a surface-emitter rather thana point-emitter device and is, thus, more suited for generalillumination purposes. The phosphor material need not be limited to theLED, but can be disposed over any transparent part of any casing orhousing. Furthermore, the MIO-LED devices of the present invention havea high CRI (e.g., >90) over a continuous, uniform, and adjustable CTrange of, for example, 3200 K to 9500 K.

FIG. 1 illustrates a chromaticity diagram 101, which is provided as areference for the discussion to follow with regard to the MIO-LEDdevices of the present invention. As is well known, a chromaticitydiagram, such as chromaticity diagram 101, is a triangular-shaped linethat connects the chromaticities of the spectrum of colors. In the caseof chromaticity diagram 101, this line defines a color triangle 111. Thecurved line within color triangle 111 of chromaticity diagram 101 showswhere the color of the spectrum lie and is called the spectral locus. Inparticular, a black body curve 113 is the spectral locus for whitelight. Combinations of colors, such as shades of blue, green, yellow,orange, and red, along black body curve 113 mix and produce white light.The colour temperatures along black body curve 113 are indicated inKelvin. Furthermore, FIG. 1 shows the range of CTs along the length ofblack body curve 113. For example, the end of black body curve 113 thatis near the blue area indicates a CT of 10000K (cool light) andapproaches infinity. By contrast, the end of black body curve 113 thatis near the red area indicates a CT of 2500K (warm light) and approacheszero. Additionally, those skilled in the art will understand that themore colors of the spectrum that are present with sufficiently highenergy levels within a white light source, the higher the CRI of thewhite light source and, thus, the higher the quality of the white light.

According to one aspect of the invention, a MIO-LED device comprisesthree or more LEDs 212, 214, 216, 312, 314, 316, 318 (FIGS. 2A to 3C)together in a housing body 210, 310 wherein

-   -   a) the light emitting parts of at least three LEDs are        encapsulated in and connected by a solid, transparent material,    -   c) said at least three LEDs (212, 214, 216, 312, 314, 316, 318)        each emit a different colour of light, whereby each colour is        selected from the group consisting of blue, red, green yellow,        orange, cyan, purple, white and magenta.

The solid, transparent material may comprise a rigid material or maycomprise a non-rigid material (e.g. with gel-like properties). Examplesof suitable solid, transparent materials include, for example, epoxy andsilicon. The solid transparent material may enclose the light emittingparts; this may mean that all the light emitted passes through the solidtransparent material, and no light may escape elsewhere. The solidtransparent material may connect the light emitting parts; this may meanthat the light emitting parts contact a common, continuous, solidtransparent material.

The solid transparent material may be blended with a quantity ofphosphor material 228 which comprises one or more phosphors activated bylight emitted from one or more of the encapsulated LEDs, so producinglight which has a wider spectrum compared with the activating light i.e.the LED, as mentioned above. Examples of suitable phosphor material 228include yttrium-aluminum-garnet phosphor (YAG-phosphor) which isactivated by blue light.

Examples of phosphors which may be present in a phosphor material 228include, but are not limited to any indicated in Tables 1, 2 or 3compounds, where the colour of light emitted is also given in brackets.Phosphors may be blended so as to give the necessary broad emissionspectrum.

TABLE 1 Phosphor materials useful according to the invention ZnS: Ag +(Zn,Cd)S: Ag (P4) (white), Y₂O₂S: Eu + Fe₂O₃ (P22R) (red), ZnS: Cu,Al(P22G) (green), ZnS: Ag + Co-on-Al₂O₃ (P22B) (blue), Zn₂SiO₄: Mn (P1,GJ), (yellowish-green (525 nm)), ZnS: Ag,Cl or ZnS: Zn (P11, BE), (blue(460 nm)), (KF,MgF₂): Mn (P19, LF) (yellow (590 nm)), (KF,MgF₂): Mn(P26, LC), (orange (595 nm)), (Zn,Cd)S: Ag or (Zn,Cd)S: Cu (P20, KA),(yellow-green), ZnO: Zn (P24, GE) (green (505 nm)), (Zn,Cd)S: Cu,Cl(P28, KE) (yellow), ZnS: Cu or ZnS: Cu,Ag (P31, GH), y(ellowish-green),MgF₂: Mn (P33, LD) (orange (590 nm)), (Zn,Mg)F₂: Mn (P38, LK), (orange(590 nm)) Zn₂SiO₄: Mn,As (P39, GR) (green (525 nm)), ZnS: Ag + (Zn,Cd)S:Cu (P40, GA) (white), Gd₂O₂S: Tb (P43, GY) (yellow-green (545 nm)),Y₂O₂S: Tb (P45, WB), (white (545 nm)), Y₂O₂S: Tb, (green (545 nm)),Y₃Al₅O₁₂: Ce (P46, KG) (green (530 nm)), Y₃(Al,Ga)₅O₁₂: Ce (green (520nm)), Y₂SiO₅: Ce (P47, BH) (blue (400 nm)), Y₃Al₅O₁₂: Tb (P53, KJ)(yellow-green (544 nm)), Y₃(Al,Ga)₅O₁₂: Tb (yellow-green (544 nm)), ZnS:Ag,Al (P55, BM) (blue (450 nm)), InBO₃: Tb (yellow-green (550 nm)),InBO₃: Eu (yellow (588 nm)), ZnS: Ag (blue (450 nm)), ZnS: Cu,Al or ZnS:Cu,Au,Al (green (530 nm)), Y₂SiO₅: Tb (green (545 nm)), (Zn,Cd)S:Cu,Cl + (Zn,Cd)S: Ag,Cl (white), InBO₃: Tb + InBO₃: Eu (amber), (ZnS:Ag + ZnS: Cu + Y₂O₂S: Eu (white), InBO₃: Tb + InBO₃: Eu + ZnS: Ag(white)

TABLE 2 Phosphor materials useful according to the invention.(Ba,Eu)Mg₂Al₁₆O₂₇ (blue), (Ce,Tb)MgAl₁₁O₁₉ (green), (Y,Eu)₂O₃(red),(Sr,Eu,Ba,Ca)₅(PO₄)₃Cl (blue), (La,Ce,Tb)PO₄ (green), Y₂O₃: Eu (red (611nm)), LaPO₄: Ce,Tb (green (544 nm)), (Sr,Ca,Ba)₁₀(PO₄)₆Cl₂: Eu (blue(453 nm)), BaMgAl₁₀O₁₇: Eu,Mn (blue-green (456/514 nm)), (La,Ce,Tb)PO₄:Ce,Tb (green (546 nm)), Zn₂SiO₄: Mn (green (528 nm)), Zn₂SiO₄:Mn,Sb₂O₃(green (528 nm)), Ce_(0.67)Tb_(0.33)MgAl₁₁O₁₉: Ce,Tb (green (543nm)), Y₂O₃: Eu(III) (red (611 nm)), Mg₄(F)GeO₆: Mn ((red (658 nm)),Mg₄(F)(Ge,Sn)O₆: Mn (red (658 nm)), MgWO₄ (pale blue (473 nm)), CaWO₄(blue (417 nm)), CaWO₄: Pb (scheelite, blue (433 nm)), (Ba,Ti)₂P₂O₇: Ti(blue-green (494 nm)), Sr₂P₂O₇: Sn, blue (460 nm), Ca₅F(PO₄)₃: Sb (blue(482 nm)), Sr₅F(PO₄)₃: Sb,Mn (blue-green (509 nm)), BaMgAl₁₀O₁₇: Eu,Mn(blue (450 nm)), BaMg₂Al₁₆O₂₇: Eu(II) (blue (452 nm)), BaMg₂Al₁₆O₂₇:Eu(II),Mn(II) (blue (450 + 515 nm)), Sr₅Cl(PO₄)₃: Eu(II) (blue (447nm)), Sr₆P₅BO₂₀: Eu (blue-green (480 nm)), (Ca,Zn,Mg)₃(PO₄)₂: Sn(orange-pink (610 nm)), (Sr,Mg)₃(PO₄)₂: Sn (orange-pinkish white (626nm)), CaSiO₃: Pb,Mn (orange-pink (615 nm)), Ca₅F(PO₄)₃: Sb,Mn (yellow),Ca₅(F,Cl)(PO₄)₃: Sb,Mn (warm white to cool white or blue or daylight),(Ca,Sr,Ba)₃(PO₄)₂Cl₂: Eu (blue (452 nm)), 3 Sr₃(PO₄)₂•SrF₂: Sb,Mn (blue(502 nm)), Y(P,V)O₄: Eu (orange-red (619 nm)), (Zn,Sr)₃(PO₄)2: Mn(orange-red (625 nm)), Y₂O₂S: Eu (red (626 nm)), (Sr,Mg)₃(PO₄)₂: Sn(II)(orange-red (630 nm)), 3.5 MgO•0.5 MgF₂• GeO₂: Mn (red (655 nm)),Mg₅As₂O₁₁: Mn (red (660 nm)), Ca₃(PO₄)₂•CaF₂: Ce,Mn, (yellow (568 nm)),SrAl₂O₇: Pb (ultraviolet (313 nm)), BaSi₂O₅: Pb (ultraviolet (355 nm)),SrFB₂O₃: Eu(II) (ultraviolet (366 nm)), SrB₄O₇: Eu (ultraviolet (368nm)), MgGa₂O₄: Mn(II), (blue-green), (Ce,Tb)MgAl₁₁O₁₉ (green).

TABLE 3 Phosphor materials useful according to the invention. Gd₂O₂S: Tb(P43) (green (peak at 545 nm)), Gd₂O₂S: Eu (red (627 nm)), Gd₂O₂S: Pr(green (513 nm)), Gd₂O₂S: Pr,Ce,F (green (513 nm)), Y₂O₂S: Tb (P45)(white (545 nm)), Y₂O₂S: Tb (P22R) (red (627 nm)), Y₂O₂S: Tb (white (513nm)), Zn(0.5)Cd(0.4)S: Ag (HS) (green (560 nm)), Zn(0.4)Cd(0.6)S: Ag(HSr) (red (630 nm)), CdWO₄ (blue (475 nm)), CaWO₄ (blue (410 nm)),MgWO₄ (white (500 nm)), Y₂SiO₅: Ce (P47) (blue (400 nm)), YAlO₃: Ce(YAP) (blue (370 nm)), Y₃Al₅O₁₂: Ce (YAG) (green (550 nm)),Y₃(Al,Ga)₅O₁₂: Ce (YGG) (green (530 nm)), CdS: In (green (525 nm)), ZnO:Ga (blue (390 nm)), ZnO: Zn (P15) (blue (495 nm)), (Zn,Cd)S: Cu,Al(P22G) (green (565 nm)), ZnS: Cu,Al,Au (P22G) (green (540 nm)), ZnCdS:Ag,Cu (P20) (green (530 nm)), ZnS: Ag (P11) (blue (455 nm)), anthracene(blue (447 nm)), plastic (EJ-212, blue (400 nm)), Zn₂SiO₄: Mn (P1)(green (530 nm)), ZnS: Cu (GS) (green (520 nm)), CsI: Tl (green (545nm)), ⁶LiF/ZnS: Ag (ND) (blue (455 nm)), ⁶LiF/ZnS: Cu,Al,Au (NDg) (green(565 nm)).

Examples of other phosphors include, but are not limited to opticalbrighteners, which act act as UV-sensitive phosphors with close-to-zeroafterglow. Usually they are organic compounds, typically found indetergents. In order to obtain a broader emission spectrum and thedesired colours, the above mentioned phosphors may be mixed according tothe practices of the skilled person.

Thus, the arrangement of a MIO-LED that includes phosphor material 228allows the production of white light by virtue of the interactionbetween the phosphor and the activating LEDs (e.g. blue emitting LED).The inventors have also found, it also allows adjustment of the CT byvirtue of the non-activating LEDs present (e.g. red or yellow when thephosphor is YAG-phosphor). Furthermore, the phosphor has an efficientdiffusing effect on the light output, meaning the light is mixed at veryclose distance; the consequence is a higher CRI compared with separate,non-diffused LEDs.

A further advantage is that the non-activating LEDs can be used toadjust minor differences in CT between any two MIO-LED devices; theconsequence is that binning (the practice by manufacturers of testingeach LED for flux, colour, voltage and placing each in a bin for giventolerances) can be eliminated.

According to one aspect of the invention, the paths of light emitted bysaid at least three LEDs (212, 214, 216, 312, 314, 316, 318) at leastpartly overlap. This requires the said LEDs to be in close proximity toeachother. Preferably, the LEDs are arranged so their paths of lightoverlap, such that their individual colours are blended when theactivated MIO-LED viewed at a distance of no less than 50 mm. Thisviewing distance may be reduced to no less than 5 mm when the diffusingphosphor is present.

3 in 1 Embodiment of a MIO-LED Device

FIG. 2A illustrates a schematic diagram of a MIO-LED (3-in-1) device 200in accordance with an embodiment of the invention. LED (3-in-1) device200 includes a device housing body 210 within which is arranged threeLEDs 212, 214, 216. The housing body 210 positions the LEDs so the pathsof light emitted thereby at least partly overlap. It also provide anappropriate projection direction for the paths of light. 3-in-1 LEDdevice 200 further includes a plurality of leads 218 that are arrangedon the perimeter of device housing body 210. More specifically, thecathode and anode of LED 212 is electrically connected to a first pairof leads 218, respectively; the cathode and anode of LED 214 iselectrically connected to a second pair of leads 218, respectively; thecathode and anode of LED 216 is electrically connected to a third pairof leads 218, respectively; as shown in FIG. 2A.

FIG. 2B illustrates a top view (not to scale) of MIO-LED (3-in-1) device200 of an embodiment of the invention. FIG. 2C illustrates across-sectional view (not to scale) of MIO-LED (3-in-1) device 200,taken along line A-A of FIG. 1B. FIGS. 2B and 2C show that LEDs 212,214, and 216 of MIO-LED (3-in-1) device 200 are arranged physically in acavity formed by the sidewalls and floor of housing body 210. Inparticular, LEDs 212, 214, and 216 are mounted on respective pedestals222 that are arranged within housing body 210, as shown in FIGS. 2B and2C. Additionally, LEDs 212, 214, and 216 are encapsulated within housingbody 210 of 3-in-1 LED device 200 by use of a solid, transparentmaterial 224, which material encloses and connects the light emittingparts.

With continuing reference to FIGS. 2A, 2B, and 2C, MIO-LED (3-in-1)device 200 is formed by a 1×3 array of LEDs. Housing body 210 may beformed of any suitably rigid, lightweight, thermally-conductive, andelectrically non-conductive material, such as, but not limited to,molded plastic or ceramic. Housing body 210 provides a cavity withinwhich LEDs 212, 214, and 216 are mounted. The cavity may be formed by aset of sidewalls and a floor, as shown in FIGS. 2B and 2C. The length,width, and height of housing body 210 may vary. An example length,width, and height may be 5.5×5.5×2.5 millimeters (mm), respectively.Leads 218 are formed of electrically conductive material, such as, butnot limited to, a gold plated copper alloy. Leads 218 may be anystandard lead structure, such as a surface-mount type lead. On a givenside of housing body 210, the spacing between leads 218 may be, forexample, 1.78 mm.

LED 212, LED 214, and LED 216 may be standard LED die devices of variousapplication- or user-defined color combinations that produce whitelight. In particular, the combination of the individual colors emittedby LED 212, LED 214, and LED 216, respectively, mix to produce a whitelight and, thereby, render 3-in-1 LED device 200 a white illuminationdevice. In a preferred embodiment, at least one of LED 212, LED 214, andLED 216 is a blue LED, while the color of the remaining two LEDs may bevary (e.g., various combinations of red, green, blue, yellow, orange,cyan, and/or magenta). The placement of the blue LED within thearrangement of LED 212, LED 214, and LED 216 is normally inconsequentiale.g. it may be flanked by LED of other colours, or may flank one of theother LEDs. In one example, LED 212 is a red LED, LED 214 is a blue LED,and LED 216 is a green LED. In another example, LED 212 is a yellow LED,LED 214 is a blue LED, and LED 216 is a cyan LED. 3-in-1 LED device 200is not limited to the examples cited above, other color combinations arepossible.

LED 212, LED 214, and LED 216 may each be mounted on a pedestal 222,respectively, which reside within a cavity formed by housing body 210.Each pedestal 222 is formed of an electrically conductive material, suchas, but not limited to, copper, aluminum, silver, or gold. By use ofeach pedestal 222, electrically conductive wires (not shown) are bondedbetween the anode and cathode of each LED and its respective pair ofleads 218 and, thus, an electrical connection is formed therebetween, asshown in FIG. 2A. Pedestals 222 and, thus, LED 212, LED 214, and LED 216may be placed on a pitch of, for example, 0.95 mm.

LED 212, LED 214, and LED 216 are encapsulated within housing body 210by use of solid, transparent material 224, which material encloses andconnects the light emitting parts. The solid, transparent material 224may comprise, for example, a transparent epoxy. The epoxy may be blendedwith and a quantity of phosphor material 228 (e.g., YAG-phosphor). Thecombination of phosphor material with a blue LED produces ahigh-brightness white light source. Epoxy, into which YAG-phosphor isblended, may be a transparent epoxy resin. Additionally, the percent ofYAG-phosphor that is present within solid, transparent material 224 maybe, for example, between 0 and 5%. One example manufacturer ofhigh-brightness while LEDs by use of YAG-phosphor in combination with ablue LED is Nichia Corporation (Japan). YAG is commonly used as thedown-conversion phosphor in white LEDs, as YAG phosphor can be excitedby the radiation from blue LEDs, which produces white light. An examplesupplier of powder phosphors consisting of micron- or submicron-sizeparticles is Nitto Denko Technical Corporation (Carlsbad, Calif.).Furthermore, another benefit of the presence of the phosphor material228 (e.g., YAG-phosphor) within the solid, transparent material 224 isthat the phosphor material 228 acts to diffuse the light that is emittedby LED 212, LED 214, and LED 216. As a result, 3-in-1 LED device 200 isconverted from a point-emitting light source to a surface-emitting lightsource, which is more suited for functional lighting applications.

With continuing reference to FIGS. 2A, 2B, and 2C, various combinationsof colored LEDs within MIO-LED (3-in-1) device 200 for producing a whitelight source that is suitable for functional lighting applications aredisclosed, e.g., red (R), green (G), blue (B), yellow (Y), orange (O),cyan (C), purple (P) and/or magenta (M). In each case, 3-in-1 LED device200 may include at least one blue LED that reacts with the YAG (i.e.,B+YAG) to produce white light. In the case wherein 3-in-1 LED device 200includes R, G, and B+YAG, the combination thereof provides the mechanismby which the CT (see FIG. 1) may be determined and adjusted, as comparedwith standard light sources. The addition of R and G provides a shiftalong black body curve 112 of chromaticity diagram 100 of FIG. 1 furthertoward the blue area, as compared with an LED with B+YAG alone.Furthermore, by varying the current that is supplied to LED 212, LED214, and LED 216, the colors of the LEDs may change slightly, which thenhas a positive effect on producing a higher CRI. In another exampleconfiguration, MIO-LED (3-in-1) device 200 may include Y, P, and B+YAG,to produce white light and to provide yet a further shift along blackbody curve 112 toward the blue area, as compared with B+YAG alone or R,G, and B+YAG. In yet another example configuration, 3-in-1 LED device200 may include Y, C, and B+YAG to produce a device with a yet higherCRI because this combination adds even more spectra to the light.

In all instances of MIO-LED (3-in-1) device 200, adding two colors, suchas R and G, to B+YAG adds more light spectra, which increases the CRIand, thus, increases the light quality.

4 in 1 Embodiment of a MIO-LED Device

FIG. 3A illustrates a schematic diagram of a MIO-LED (4-in-1) device 300of a second embodiment of the invention. MIO-LED (4-in-1) device 300includes a housing body 310 within which is arranged four LEDs 312, 314,316, 318. MIO-LED (4-in-1) device 300 further includes a plurality ofleads 320 that are arranged on the perimeter of housing body 310. Morespecifically, the cathode and anode of LED 312 may be electricallyconnected to a first pair of leads 320, respectively; the cathode andanode of LED 314 may be electrically connected to a second pair of leads320, respectively; the cathode and anode of LED 316 may be electricallyconnected to a third pair of leads 320, respectively; the cathode andanode of LED 318 may be electrically connected to a fourth pair of leads320, respectively; as shown in FIG. 3A.

FIG. 3B illustrates a top view (not to scale) of MIO-LED (4-in-1) device300 of the second embodiment of the invention. FIG. 3C illustrates across-sectional view (not to scale) of the MIO-LED (4-in-1) device 300,taken along line B-B of FIG. 3B. FIGS. 1B and 1C show that LEDs 312,314, 316, and 318 of MIO-LED (4-in-1) device 300 are arranged physicallyin a cavity formed by the sidewalls and floor of housing body 310. Inparticular, LEDs 312, 314, 316, and 318 are mounted on respectivepedestals 322 that are arranged within housing body 310, as shown inFIGS. 3B and 3C. Additionally, LEDs 312, 314, 316, and 318 areencapsulated within housing body 310 of 4-in-1 LED device 300 by use ofa solid, transparent material 324, which may be formed, for example,from a transparent epoxy; the epoxy might be blended, with a quantity ofYAG-phosphor 328, as shown in FIG. 3C.

With continuing reference to FIGS. 3A, 3B, and 3C, MIO-LED (4-in-1)device 300 may be formed by a 1×4 array of LEDs. Alternatively, MIO-LED(4-in-1) device 300 may be formed by a 2×2 array of LEDs. Anyarrangement is within the scope of the invention. Housing body 310 maybe formed of any suitably rigid, lightweight, thermally-conductive, andelectrically non-conductive material, such as, but not limited to,molded plastic or ceramic. Housing body 310 provides a cavity withinwhich LEDs 312, 314, 316, and 318 are mounted. The cavity is formed by aset of sidewalls and a floor, as shown in FIGS. 3B and 3C. The length,width, and height of housing body 310 may vary. An example length,width, and height may be 6.5×5.5×2.5 mm, respectively. Leads 320 areformed of electrically conductive material, such as, but not limited to,a gold plated copper alloy. Leads 320 may be any standard leadstructure, such as a surface-mount type lead. On a given side of housingbody 310, the spacing between leads 320 may be, for example, 1.78 mm.

LED 312, LED 314, LED 316, and LED 318 may be standard LED die devicesof various application- or user-defined color combinations that producewhite light. In particular, the combination of the individual colorsemitted by LED 312, LED 314, LED 316, and LED 318, respectively, mix toproduce a white light and, thereby, render 4-in-1 LED device 300 a whiteillumination device. In a preferred embodiment, at least two of LED 312,LED 314, LED 316, and LED 318 are blue LEDs, while the color of theremaining two LEDs may be vary (e.g., various combinations of red,green, blue, yellow, orange, cyan, and/or magenta). The placement of thetwo blue LEDs within the physical 1×4 or 2×2 array arrangement of LED312, LED 314, LED 316, and LED 318 is inconsequential. In one example,LED 312 is a red LED, LED 314 is a blue LED, LED 316 is a blue LED, andLED 318 is a green LED i.e. red may be adjacent to blue, which isadjacent to another blue, which is adjacent to green. In anotherexample, LED 312 is a yellow LED, LED 314 is a blue LED, LED 316 is ablue LED, and LED 318 is a cyan LED i.e. yellow may be adjacent to blue,which is adjacent to another blue, which is adjacent to cyan. MIO-LED(4-in-1) device 300 is not limited to the examples cited above; othercolour combinations and arrangements are possible.

LED 312, LED 314, LED 316, and LED 318 may each be mounted on pedestals322, respectively, which reside within the cavity formed by housing body310. Each pedestal 322 may be formed of an electrically conductivematerial, such as, but not limited to, copper, aluminum, silver, orgold. By use of each pedestal 322, electrically conductive wires (notshown) may be bonded between the anode and cathode of each LED and itsrespective pair of leads 320 and, thus, an electrical connection isformed therebetween, as shown in FIG. 3A. Pedestals 322 and, thus, LED312, LED 314, LED 316, and LED 318 may be placed on a pitch of, forexample, 0.95 mm.

LED 312, LED 314, LED 316, and LED 318 are may be encapsulated withinhousing body 310 by use of a solid, transparent material 324, whichmaterial encloses and connects the light emitting parts. Solid,transparent material 324 may comprise, for example, a blend oftransparent epoxy (e.g., epoxy 326); the solid, transparent materialepoxy might be blended with a quantity of phosphor material (e.g.,YAG-phosphor 328). The combination of phosphor material with a blue LEDproduces a high-brightness white light source. Epoxy 326 andYAG-phosphor 328 of solid, transparent material 324 are substantiallyidentical in form and function to epoxy and YAG-phosphor of the solid,transparent material 224, as described in FIGS. 2A, 2B, and 2C. Again, abenefit of the presence of phosphor material (e.g., YAG-phosphor 328)within epoxy is that the phosphor material acts to diffuse the lightthat is emitted by LED 312, LED 314, LED 316, and LED 318. As a result,MIO-LED (4-in-1) device 300 is converted from a point-emitting lightsource to a surface-emitting light source, which is more suited forfunctional lighting applications.

Because blue LEDs tend to have a shorter lifetime than R and G, thepresence of two blue LEDs in the MIO-LED device allows the user toactivate one blue LED only and then activate the second blue LED onlywhen the first blue LED begins to fail. Alternatively, both blue LEDsmay be activated simultaneously, but at a reduce power level, whichprolongs their lifetime. In both cases, a technique is provided forprolonging the overall lifetime of the device due to failure of the blueLED. An additional benefit of including two blue LEDs is that in theevent that, should the solid-transparent material discolor (e.g. turnbrown) over time, activating the second blue LED can help overcome thelosses due to the aged transparent material. This technique can also beapplied to other LEDs dependent on their lifetime characteristics.

In the case wherein MIO-LED (4-in-1) device 300 includes R, G, B+YAG,and B+YAG, the combination thereof provides the mechanism by which theCT may be determined and adjusted, as compared with standard lightsources. Furthermore, by varying the current that is supplied to LED312, LED 314, LED 316, and LED 318, the colors of the LEDs may changeslightly, which then has a positive effect on producing a higher CRI.Additionally, 4-in-1 LED device 300 or higher (>4-in-1) MIO-LED deviceprovides a yet further expanded (multi-spectra) device as compared with3-in-1 LED device 200, which results in a yet higher CRI.

In another example configuration, MIO-LED (4-in-1) device 300 includesR, G, O and B+YAG, which provides a yet further expanded (multi-spectra)device for achieving a yet higher CRI. Because all three LEDs of MIO-LED(3-in-1) device 200 and MIO-LED (4-in-1) device 300 are activatedsimultaneously, their power rating may be reduced for a certainillumination as compared with one white LED only that produces the sameillumination. For example, each LED may dissipate 250 watts only ascompared to one device that dissipates 1 to 5 watts. Therefore, thethermal management system (not shown) for MIO-LED devices of the presentinvention (e.g. MIO-LED (3-in-1) device 200 or MIO-LED (4-in-1) device300) may be simplified as compared with high-power LEDs. Additionally,the combination of multiple (e.g., three or four) LEDs in a singlepackage produces a surface-emitter device, instead of a point-emitterdevice.

In the case wherein MIO-LED (4-in-1) device 300 includes R, G, B+YAG,and B+YAG, the combination thereof provides the mechanism by which theCT may be determined and adjusted, as compared with standard lightsources. Furthermore, by varying the current that is supplied to LED312, LED 314, LED 316, and LED 318, the colors of the LEDs may changeslightly, which then has a positive effect on producing a higher CRI.Additionally, 4-in-1 MIO-LED device 300 (or other >4-in-1 MIO-LEDdevice) provides a yet further expanded (multi-spectra) device ascompared with 3-in-1 LED device 200, which results in a yet higher CRI.

Separate leads for each LED of MIO-LED (3-in-1) device 200 and MIO-LED(4-in-1) device 300 (or other >4-in-1 MIO-LED device) allows individualcontrol of forward bias voltage (e.g., R=2 volts, B and G=4 volts).However, the present invention is not limited to separate leads.Alternatively, 3-in-1 LED device 200 and MIO-LED (4-in-1) device 300 mayinclude a common lead to drive multiple LEDs when operating, forexample, in a common anode or common cathode configuration.

Because the human eye is very sensitive to variations in white light,combining R and G with B+YAG provides a mechanism for obtaining a highCRI. Compensating the individual color differences between the MIO-LEDsB+YAG alone provides a broad range of about 75% CRI, but adding R and Gto B+YAG allows, for example, the device to be adjusted to 6900K andheld constant. Adding R and G to B+YAG allows compensation to move lightalong the CT curve (see FIG. 1). The result is a MIO-LED device (e.g. aMIO-LED (3-in-1) device 200 or MIO-LED (4-in-1) device 300) of thepresent invention provide a white light illumination device that has aCT in the range of 3200K to 9500K and a CRI of 90 and above.

Other Embodiments of a MIO-LED Device

Furthermore, the present invention is not limited to MIO-LED 3-in-1 and4-in-1 devices, n-in-1 devices are possible. For example, a 6-in-1device may be formed by use of R, G, B+YAG and Y, C, B+YAG. R, G, B+YAGallows of CT shift toward red only, whereas Y, C, B+YAG further allows aCT shift toward blue (See FIG. 1). In this example, furtheradjustability is provided. In all examples of MIO-LED (3-in-1) device200, MIO-LED (4-in-1) device 300, and n-in-1 devices, adding two or morecolors, such as R and G, to B+YAG adds more light spectra, whichincreases the CRI and, thus, increases the light quality. It can alsogive the user the opportunity to optimize for different lightingrequirements.

Furthermore, in all examples of MIO-LED (3-in-1) device 200, MIO-LED(4-in-1) device 300, and n-in-1 devices, the solid, transparent materialmay be silicon based instead of epoxy based, as the use of silicon mayincrease the lifetime of the device. Additionally, in all examples ofMIO-LED (3-in-1) device 200, MIO-LED (4-in-1) device 300, and n-in-1devices, the LEDs may be replaced with organic LED (OLED) devices toproduce a white light source that is suitable for functional lightingapplications.

Modules and Methods Incorporating MIO-LEDs

One embodiment of the present invention is a module 100 thatincorporates a plurality of MIO-LED devices as described above. In thefollowing description, reference is made to FIG. 4 which depicts aplurality of MIO-LED devices 120 present in a module 100. The pluralityof MIO-LED devices 120 (e.g. 120-1) may configured as an LED array 118.The LED array comprises an arrangement of LEDs, which together projectlight from the array, combining their light output. The array maycomprise columns and rows as depicted in FIG. 5. However it is notlimited to such as arrangement, and may alternatively be arranged, forexample, circularly, spirally, irregularly etc.

The array may comprise, for example, a RGB+YAG MIO-LED (3-in-1) devicethat is described above. Because the B+YAG LED produces white light, theRGB+YAG MIO-LED device is referred to as the RGW MIO-LED device. Inanother example, an MIO-LED device 120 of LED array 118 may be anorange, cyan, and blue (OCB) MIO-LED device that is described above. Twoor more MIO-LED devices 120 may be different, for example, the array 118may comprise various combinations of MIO-LED devices described above,such as a combination of RGW and OCB MIO-LED devices. More details of anexample LED configuration that includes a combination of two MIO-LEDdevices are described with reference to FIG. 4. The MIO-LED devicesdescribed may be 3-in-1 devices, i.e. having only three LEDs, or maycomprise additional LEDs so forming, for example, a 4-in-1, 5-in-1,6-in-1 etc. device.

Current sources 122-1 through 122-n are associated with MIO-LED devices120-1 through 120-n, respectively, and each represents multiple currentsource devices (e.g. a current source 122 for the R LED, a currentsource 122 for the G LED, and a current source 122 for the W LED). Thus,each of the LEDs within each MIO-LED device 120 may have a dedicatedcurrent source 122.

Current sources 122 may be any commercially available constant currentsources that are capable of supplying a constant current, typically inthe range of 5 to 80 milliamps (mA), to MIO-LED devices 120. One exampleconstant current device includes, but is not limited to, the DM13216-channel PWM-controlled constant current driver, supplied by SiliconTouch Technology Inc. (Taiwan).

The module 100 of the present invention may comprise a DAC 124 that isconnected to the MIO-LED devices 120 so as to control the brightness ofeach LED, or of a set (e.g. 2, 3, 4, 5, 6 or more) of LEDs therein.Thus, there may be one DAC per LED or one DAC per set of LEDs. Where oneDAC 124 controls a set of LEDs, the LEDs in the set may be the samecolour. This allows an arrangement a cluster of MIO-LEDs devices (e.g.2, 3, 4, 5 or 6 or more) is controlled by one DAC 124 for each colour ofLED present. For example, where the MIO-LEDs devices in a cluster eachcontain RGB+YAG LEDs, there may be 3 DACs 124 controlling this cluster,one for each colour present in each MIO-LED device.

An example of a configuration of the DAC 124 present in an LED circuit110 is shown in FIG. 4. The DAC 124 may be any commercially availabledigital-to-analog converter device. DAC 124 may have, for example,8-bit, 10-bit, or 12-bit resolution. The digital input of DAC 124 may beprovided by DSP 112 and multiple analog outputs of DAC 124 feedrespective current sources 122. As a result, DAC 124 is used for settingthe current value of each current source 122 according to the digitalinput of DAC 124. LED circuit 110 is not limited to a single DAC 124that feeds all current sources 122, as shown in FIG. 4. Alternatively,LED circuit 110 may include a combination of multiple DACs 124 in orderto set the current values of current sources 122. In one example, DACdevice may be, but is not limited to, the AD5308 8-channel DAC, suppliedby Analog Devices (Norwood, Mass.).

Each of the LEDs within MIO-LED device 120 may be connected to adedicated PWM switch 126 which permits on/off control of the MIO-LED 120or of each LED therein, using a signal. For example, pulse-widthmodulation (PWM) switches 126-1 through 126-n are associated withMIO-LED devices 120-1 through 120-n, respectively; each may representmultiple PWM switch devices (e.g., a PWM switch 126 for the R LED, a PWMswitch 126 for the G LED, and a PWM switch 126 for the W LED). Each PWMswitch 126 (e.g., each PWM switch 126-1 through 126-n) of LED circuit110 may be an electronic switch, such as a FET switch, that is used toconnect or disconnect a given current source 112 from its respective LEDvia a PWM signal (not shown) that is generated by DSP 112. As is wellknown, pulse width modulation is a technique for controlling an analogcircuit, such as LED circuit 110, with the digital outputs of aprocessor, such as DSP 112. Each LED within a MIO-LED device 120 mayhave a dedicated combination of one current source 122 and one PWMswitch 126, which allows individual control of each LED within theMIO-LED device, which is represented by one MIO-LED device 120 in FIG.4.

The PWM switch 126 may be used to dim a MIO-LED device 120. Thetechnique of PWM dimming is useful, since it allows the colour output ofan LED to remain essentially constant as the current is not alteredduring dimming (only the duration of pulses provided to an LED).However, it is not the most efficient dimming method, since the currentsupplied to the LED remains the same using PWM dimming even at very lowlight outputs. The present invention, instead, may employ currentdimming. It may overcome the changes in colour output of an MIO-LEDdevice 120 at different currents by characterising a MIO-LED device atvarious currents. The system may overcome changes in colour output atdifferent currents by altering the relative colour output of each LEDwithin said MIO-LED device 120. This characterisation may be performedin the factory, and the association between current, colour and lightoutput provided as information held in a memory which the DSP canaccess. According to one aspect of the invention, dimming is performedusing a mixture of PWM control and current control.

Storage device 128 of LED circuit 110 may be present in a module 100 ofthe present invention configured to provide data to the DSP 112. Storagedevice 128 storage device is connected so as to provide information to aDSP 112 regarding behavior of the module. Example of color informationthat may stored in storage device 128 includes, but is not limited to,current vs. color behavior and light output vs. temperature. The storagedevice 128 may be any non-volatile storage medium, such as a randomaccess memory (RAM) device, a programmable read-only memory (PROM)device, or erasable programmable read-only memory (EPROM) device. Thestorage capacity of storage device 128 is equal to or greater than thatrequired to store color data for each MIO-LED device 120, which is usedfor color compensation of each MIO-LED device 120, as needed, during theoperation of LED module system 100.

The color data that is stored in a storage device 128 may be determinedat the time that the components of LED circuit 110 are assembled (i.e.,at manufacture). This color data may be stored within storage device 128at the time of assembly or, alternatively, stored when LED module system100 is placed in the field.

The module 100 of the present invention, may comprise one or moretemperature sensors 130 configured to provide data to the DSP 112 asindicated in LED circuit 110. Temperature sensors 130 are commerciallyavailable temperature sensing devices for sensing the operatingtemperature of the physical instantiation of LED module system 100, suchas a printed circuit board that is associated with LED circuit 110. Inparticular, a plurality of temperature sensors 130 may be installed inclose proximity to the physical instantiation of LED array 118 and in adistributed fashion with respect to the area consumed by LED array 118.The outputs of temperature sensors 130 are fed to DSP 112, in order forDSP 112 to apply color compensation of MIO-LED devices 120 that is basedon temperature variations. Additionally, temperature sensors 130 may beused to measure the internal temperature of the packaging (FIGS. 5 to10) of LED module system 100. DSP 112 may use the information fromtemperature sensors 130 to control cooling mechanisms of the packagingof LED module system 100, in order to maintain a constant temperaturetherein. In one example, temperature sensor device may be, but is notlimited to, the AD7415 temperature sensor, supplied by Analog Devices(Norwood, Mass.).

The module 100 of the present invention may comprise one or more IRsensors 132. The IR sensor may be configured to provide a signal to theDSP 112 as indicated in LED circuit 110. The IR sensor 132 may be acommercially available IR sensing device for sensing IR signals from aremote control device (not shown), which is used for operating LEDmodule system 100. A digital output of IR sensor 132 feeds DSP 112,which interprets and responds to the remote control commandsaccordingly. One example IR sensor device includes, but is not limitedto, the TSOP 341 IR sensor, supplied by Vishay Intertechnology,Inc.(Malvern, Pa.). Remote control functions that are received via IRsensor 132 and interpreted by use of DSP 112 include, but are notlimited to, brightness adjustment, individual color adjustment, patternselection, color temperature selection, CRI selection, and so forth. Theremote control device (not shown) may be any commercially availableuniversal remote control unit, such as used with televisions or DVDplayers. One example remote control unit that is suitable for use withLED module system 100 is the Philips ProntoPRO TSU6000 universal remotecontrol device, supplied by Royal Philips Electronics N.V, (Amsterdam,Netherlands).

DSP 112 of LED module system 100 may be a general-purpose microprocessorfor processing standard microprocessor instructions. DSPs usuallysupport a set of specialized instructions to perform commonsignal-processing computations quickly. In one example, DSP device maybe, but is not limited to, the TI2802 DSP by Texas Instruments (Dallas,Tex.). DSP 112 manages the overall operation of LED module system 100.Functions that are managed by use of DSP 112 and that providemulti-functionality to LED module system 100 include, but are notlimited to, communications control, on/off control of individual MIO-LEDdevices 120, on/off control of entire LED array 118, cooling systemcontrol, power management control, variable brightness control (i.e.,dimming), variable color control, variable operating efficiency control,and variable CRI control. In doing so, the operations of DSP 112include, but are not limited to, the following:

-   interpreting and responding to control information that is received    via IR sensor 132 from a remote control device;-   interpreting and responding to control information that is received    via network interface 114 from an external controller device, such    as a computer;-   interpreting information that is received from temperature sensors    130, in order to control a cooling mechanism (not shown); p0    interpreting information that is received from temperature sensors    130, in order to apply temperature compensation as needed to LED    circuit 110 that is based on information, such as light output vs.    temperature data, within storage device 128; and-   applying color compensation as needed to LED circuit 110 that is    based on information, such as current vs. color behavior data,    within storage device 128.

In performing the above operations, the function of DSP 112 is tocalculate constantly the optimal values for controlling the light outputof each MIO-LED device 120. When DSP 112 receives a request for acertain amount of light for a certain color, DSP 112 responds such thatLED circuit 110 is optimized for efficiency or for CRI.

The DSP 112 may be configured so that the CT and brightness of the lightemitted from each MIO-LED device 120 is adjusted to be identical. Inother words, the DSP 112 may send control signals which adjust the powerto the LEDs, such that the CT and brightness of the light emitted fromeach MIO-LED device 120 is uniform within each module. As mentionedabove, the DSP may be configured to maintain the CT and brightness.

Alternatively, the DSP 112 may be configured to adjust the CT andbrightness of the light emitted from each MIO-LED device 120. Thisapplication may be useful when a module 100 is used as part of a monitorfor the display of images such as video, static pictures or computer.

The module 100 of the present invention may comprise one or more Networkinterfaces 114. The Network interface 114 may be configured to exchangecontrol signal and data with the DSP 112 as indicated in LED circuit110. Network interface 114 of LED module system 100 provides acommunications interface between LED module system 100 and an externalcontrol device, such as a computer (not shown). The design of networkinterface 114 may be communication protocol-specific. Alternatively, thedesign of network interface 114 may support multiple communicationprotocols.

Communication protocols that may be supported by network interface 114include, but are not limited to, Digital Addressable Lighting Interface(DALI); DMX/DMX512 and DVI/HDMI, which are digital video/data protocols;Recommended Standard 232 (RS-232); Recommended Standard 485 (RS-485);Controller Area Network (CAN); Serial Digital Interface (SDI); HighDefinition Serial Digital Interface (HD SDI); Ethernet; Art-NetEthernet; ZigBee wireless; and Bluetooth wireless.

Power supply 116 of LED module system 100 is configured to receive asource of power (e.g. 90-250 VAC, 50-60 Hz), and transform it, ifnecessary, for supply to the LEDs and other components. The power supply116 may be a custom switch-mode power supply. As is well known, aswitch-mode power supply incorporates power-handling electroniccomponents that are continuously switching on and off with highfrequency and, thus, the output voltage is controlled by varying dutycycle, frequency, or a phase of these transitions. The input of thepower supply 116 may be an alternating current (AC) voltage (VAC) in therange of 90-264 VAC, 50-60 Hz. For example, the input voltage may be 110or 220 VAC. Alternatively, input of power supply 116 may be obtainedfrom an electromagnetic induction source as described below. The powersupply 116 may be designed to provide, for example, 25 watts and mayinclude a power factor correction (PFC) feature, which is a technique ofcounteracting the undesirable effects of electric loads that create apower factor (p.f.) that is less than 1. Power supply 116 provides powerfor all active electronic devices within LED module system 100. Inparticular, power supply 116 produces multiple LED voltages (V-LEDs ofLED circuit 110) for powering MIO-LED devices 120, which includes LEDsof different colors (each color requires a different V-LED voltage).Table 4 below shows example DC voltages that are associated with eachLED color.

TABLE 4 Example V-LED voltages LED color DC volts RED 2.5 max GREEN 3.5max WHITE (B + YAG) 3.5 max BLUE 3.5 max CYAN 4.0 max ORANGE 3.3 max

According to one embodiment, the invention, the voltage output of thepower supply 116 is adjustable according to the required power. Forexample, e.g. a white LED may have a max V-LED voltage of 3.5V specifiedat 20 mA current. Another LED may have a V-LED of 3.2V specified at 10mA of current. When optimizing for efficiency, the power supply maybeconfigured to receive a signal from the DSP to adjust the voltageoutput, for example, from 3.5V to 3.2V.

Additionally, power supply 116 may provide power for a cooling fan(shown in FIGS. 6 and 8) that is associated with the packaging of LEDmodule system 100. The output voltage for the cooling fan may be, forexample, in the range of 2 to 5 volts DC. Alternatively, the DC voltagemay be held constant and the fan may be driven using PWM. The power ofthe fan may thus be regulated. This is advantageous where it isimportant to maintain efficiency i.e. reduce power input by reducing fanactivity, or to reduce noise also by reducing fan activity.

Additionally, the LED module system 100 may include a rechargeablebattery (not shown), which provides power to LED module system 100 ofmodular LED device 200 in the event that AC power source is lost. It maybe charged by power regulator 116 when the power source is present.

While the use of AC or DC power is mentioned above, the power input tothe power supply 116 may be directly or indirectly using electromageticinduction. Thus, the LED module system 100 may include a receiving partfor an inductively coupled power. In such a system, an induction coil(secondary coupler), part of LED module system 100, receives power byinduction from an external coil (primary coupler). The external coil maybe integrated into a supporting frame for the system. This may allow theLED module system to operate without power cables, so greatlysimplifying setting up the system. The power transferred by theinductive arrangement may range from sub 1 Watt (e.g. 100 mW) tohundreds of Watts.

An implementation of inductive coupling to transfer energy from a powersource towards the lighting system is exemplified in FIG. 14. Anexternal inductive power supplier 2010 comprises a primary coupler 2005that receives power 2001 from a main source (e.g. mains AC power at 50Hz, or AC current at 1 to 200 kHz) through cables 2003. The inductivepower supplier 2010 may convert the power 2001 as necessary and provideit to the primary coupler 2005 in a form that can be transmittedwirelessly to a receiving coil (secondary coupler) 2006 that is part ofthe LED module system 100. Additional circuitry 2002, 2004 may bepresent in the inductive power supplier 2010 to perform the task of, forexample, converting the power source 2001 to a high-frequency waveform,and/or to receive/transmit data information utilising the primarycoupler 2005; the inverter 2002 (if necessary), and data modulatorand/or demodulator 2004 are respectively indicated in FIG. 14.

The LED module system 100 may comprise a secondary coupler 2006 whichreceives wirelessly power by inductive coupling from the primary coupler2005. The power output 2009 is provided directly or indirectly as theinput to the power supply 116 described above. Additional circuitry2007, 2008 may also be present in the LED module system 100 to controlthe voltage of the power output 2009, and/or to add receive/transmitdata information utilising the secondary coupler 2006; the voltagecontroller 2007, and data modulator and/or demodulator 2008 arerespectively indicated in FIG. 14.

The respective primary 2005 and secondary 2006 couplers may have anysuitable shape. Some shapes might have advantages for efficiency of theenergy transfer and some shapes might be optimised so as to allow easymounting or clicking of the light source onto the couplers primary. Somecoupler shapes may allow a flat panel design of both couplers.

Besides using the couplings 2005, 2006 to transfer energy, data transfermay also be exchanged over the couplings 2005, 2006. Data transfer maybe bidirectional, i.e. both from the LED module system 100 to the powersupplier 2010 and vice versa. Data transfer might be implemented usingvarious modulation techniques (e.g. phase shift key modulation). Thistechnique avoids connections (connectors or plugs) between light sourcesand the power source and data source. Hence the lamp source can behermetically closed or sealed for e.g. outdoor use to a certain IPprotection level.

The primary coupler 2005 may be integrated within a frame or holdingmechanism which mechanically supports the LED module system 100 orhousing thereof. The primary coupler 2005 may be included in a cable,possibly connecting more LED module systems 100, which connects to apower source. Via cabling, a plurality of primary couplers 2005 can beinterconnected to form a 2D or 3D shape of light sources.

As mentioned above, inductive power supplier 2010 may be incorporateadditional circuitry 2002 for converting energy to a waveform frequencysuitable for power transfer system; an example of this is show shown(FIG. 15) which depicts an inverter 2002 receiving DC power, whichconverts it into higher frequency power (e.g. 1 to 200 kHz) for use bythe primary coupler 2005.

As mentioned above, inductive power supplier 2010 may incorporateadditional circuitry 2002 for generating data transfer (unidirectionalor bidirectional) 2012, 2013 if applicable; an example of this is shown(FIG. 16) which depicts a data modulator and/or demodulator 2008receiving DC power.

The inductive power supplier 2010 may be incorporate additionalcircuitry 2015 configured to detect the position of the light source ina string 2012 (or matrix) of light sources (FIG. 17).

As mentioned above, the inductive power supplier 2010 may be poweredfrom traditional mains power (e.g. 120-250 V AC, 50-60 Hz). However, itmay alternatively receive power from a high frequency inverter (e.g. 6to 250V AC, 1-200 kHz). According to one embodiment of the invention,high frequency power for the primary coupler 2001 is separately providedto the inductive power supplier 2010 via a common rail 2013. Suchconfiguration is indicated in FIG. 18. According to another aspect ofthe invention, mains power or DC power is provided to the inductivepower supplier 2010 via a common rail 2014, which power is used tooperate the circuitry and the primary coupling via an inverter 2002. Theuse of common rails allows several light sources to be convenientlycoupled to a plurality of inductive power suppliers 2010, where by thepower source 2001 is available on common rails. Any common rails 2011,2013, 2014, or cables connecting the inductive power supplier 2010 canbe sealed for outdoor use.

According to one aspect of the invention the common rails 2011, 2013,2014, connecting the primary coupler 2001 are hermetically sealedoutdoor or underwater use.

By changing the power output of the primary coupler, light emitted bythe LED module system 100, can be controlled. Such control might be inaddition to or an alternative to any electronic control already presentin the LED module systems 100.

The LED module system 100 may incorporate electronics e.g. a voltagecontroller 2007, configured to adjust power or voltage or currentreceived from the secondary coupling 2006. This can be used tocompensate for changes in energy received, compensate for tolerances ofthe coupler and the electronic components, variance in the gap of thewireless coupling.

The LED module system 100 may incorporate electronics e.g. a datamodulator and/or demodulator 2008, so as to receive digital data fromthe primary side and may contain electronics so as to transmit data tothe primary side as already mentioned above.

The LED module system 100 may incorporate may contain any IR receiver ortransceiver so as to be able adjust the functionality of the lightsource. This data also might be transmitted to inductive power supplier2010 for use on a network or to control other light sources in thesystem.

The LED module system 100 may incorporate any wireless receiver and/ortransmitter to communicate with other light sources or control devicesfor the lighting system.

The LED module system 100 may attach to the primary coupler inductivepower supplier 2010 part of the inductive power supplier 2010 by amounting. Such mounting includes a clickable mounting.

The LED module system 100 may also be hermetically sealed outdoor orunderwater application is possible.

With continuing reference to FIG. 4, the operation of LED module system100 may be as follows. DSP 112 receives commands from a remote controldevice via IR sensor 132 or from an external controller via networkinterface 114 and, thus, a user activates LED circuit 110.

Subsequently, a user selects one or more functions or modes of operationof LED module system 100 and LED circuit 110 is set accordingly. Forexample, a user selects a desired brightness, color, efficiency, and/orCRI. DSP 112 interprets and responds to the user selections by queryingthe information in storage device 128 for each MIO-LED device 120 andcalculating the required current value for controlling each MIO-LEDdevice 120. DSP 112 then sets each current source 122 accordingly viaDAC 124. Additionally, DSP 112 monitors continuously temperature datafrom temperature sensors 130 in order to apply temperature compensation,as needed, and in order to control the cooling system (not shown).Optionally, the correction for achieving uniform color from one MIO-LEDdevice 120 to its neighbors is accomplished digitally via PWM switches126, while the general light output of each MIO-LED device 120 iscontrolled via current sources 122. Controlling the light output viacurrent allows for maximum operating efficiency. Additionally, by usingthe correction data that is stored in storage device 128, peak colorrendering and color output levels may be ensured. In summary, theoperation of LED module system 100 utilizes the combination of analogLED drive and digital compensation. The electronics of LED module system100 provides feedback mechanisms by which DSP 112 may calculate and,therefore, adjust, for example, brightness, CRI, and CT.

FIG. 5 illustrates a perspective front view of a modular LED device 201,which comprises a housing and an LED module system 100 of FIG. 4.Modular LED device 201 is the physical instantiation of a modular LEDdevice that provides a generic building block that is easy to use andsuitable for multiple lighting applications. Modular LED device 201 mayinclude an LED board 250 upon which is mounted the components of LEDcircuit 110 of LED module system 100 of FIG. 5. Modular LED device 201may further include a housing/heatsink 252. Housing/heatsink 252 servesas the package for all electrical components of LED module system 100and facilitates the thermal management system. Additionally, modular LEDdevice 201 may include a set of screws/spacers 254 for fastening LEDboard 250 to housing/heatsink 252 and, optionally, for optionallyattaching one or more optical devices (e.g., lens, filter, diffuser) tothe face of LED board 250. Optionally, the outer face of LED board 250may include silicon layer, in order to provide a barrier againstcontamination or water intrusion.

Also shown in FIG. 5 is a Detail A of a 3-in-1 LED device 256, which isone example of one MIO-LED device 120 of LED circuit 110 of LED modulesystem 100 of FIG. 1. FIG. 5 shows that 3-in-1 LED device 256 includes,for example, three LEDs 258. LEDs 258 may be, for example, RGW or OCBLEDs to form a RGW or OCB MIO-LED device, as described above.

FIG. 6 illustrates a perspective back view of modular LED device 201,which comprises a housing and an LED module system 100 of the presentinvention. FIG. 6 shows that modular LED device 201 further including aset of click points 220 that are installed in housing/heatsink 252, acooling fan 260 mounted in the rear of housing/heatsink 252 that issecured by a fan guard 262, an AC power port 226, and one or more (e.g.,two) I/O ports 264.

Referring again to FIGS. 5 and 6, LED board 250 may be a multi-layerprinted circuit board (PCB) for implementing LED circuit 110 of LEDmodule system 100 of FIG. 4. In particular, the outer face of LED board250, as shown in FIG. 5, is a physical instantiation of LED array 118 ofLED circuit 110, where MIO-LED devices (e.g. 3 in 1) 256 of LED board250 equate to MIO-LED devices 120 of LED circuit 110. Mounted on theinner side (not shown) of LED board 250 are the supporting electricalcomponents of LED circuit 110 (e.g., current sources 122, DAC 124, PWMswitches 126, storage device 128, temperature sensors 130, and IR sensor132). In particular, temperature sensors 130 (not visible) are installedin a distributed fashion across the area of LED board 250.

Additionally, a small hole (not shown) that is associated with IR sensor132 is provided within LED board 250, in order to provide aline-of-sight port for receiving IR signals from a remote controldevice.

FIG. 9 illustrates a cross-sectional view of modular LED device 201,which comprises a housing and the LED module system 100 of the presentinvention. taken along line A-A of FIG. 2. FIG. 9 shows PCB assembly 230as well as mounting plate 238 secured within housing/heatsink 252.Additionally, FIG. 9 shows that housing/heatsink 252 includes aplurality of cooling fins 240 for providing a large surface area fromwhich to dissipate heat. Furthermore, the outer cooling fins 240 may betapered at an angle α, such that the portion of housing/heatsink 252that accommodates LED board 250 has a greater dimension than theopposite portion of housing/heatsink 252. Angle α may be in the rangeof, for example, 2 to 15 degrees, with a specific example of 4 degrees.Although a single modular LED device 201 may be used as a standalonelighting device, in the case of an LED lighting device that is formed ofa configuration of multiple generic modular LED devices 201, the taperedsides of modular LED device 201 allow multiple modular LED devices 201to be assembled one to another with a slight curvature. The taperedmodular LED device 201, therefore, allows its use in a lightingapplication that requires a curved surface, again demonstrating themulti-functionality of modular LED device 201.

FIG. 10 illustrates a front view of a housing/heatsink 252 of modularLED device 201 that houses LED module system 100 of the presentinvention. In particular, FIG. 10 shows the portion of housing/heatsink252 that accommodates LED board 250 and mounting plate 238. FIG. 10shows that housing/heatsink 252 further includes a set of alignmentnotches 242 and alignment detents 244 that are arranged along its outerperimeter. Although a single modular LED device 201 may be used as astandalone lighting device, in the case of an LED lighting device thatis formed of a configuration of multiple generic modular LED devices201, the combination of click points 220 (shown in FIG. 6), alignmentnotches 242, and alignment detents 244 provide mechanisms for easyassembly of modular LED devices 201 to another. For example, alignmentnotches 242 of one modular LED devices 201 are easily aligned and fittedto alignment detents 244 of a neighboring modular LED devices 201.

Likewise, click points 220 of one modular LED devices 201 may easilyaligned and fitted to click points 220 of a neighboring modular LEDdevices 201. Accordingly, modular LED device 201 provides a universalbuilding block for forming a lighting device for any lightingapplication.

Referring again to FIGS. 5 and 6, housing/heatsink 252 may be formed ofa material, such as, but not limited to, aluminum or magnesium, that hashigh thermal conductivity and that is lightweight. The design ofhousing/heatsink 252 in combination with cooling fan 260 providesuniform heat transfer throughout modular LED device 201 and, thus,provides uniform heat dissipation. The inner portion (not visible) ofhousing/heatsink 252 may include built-in airflow guides, in order todistribute effectively the airflow from cooling fan 260 to hotspotswithin modular LED device 201. Housing/heatsink 252 may further includeclearances for installing the electronics (e.g., in the form of PCBs)that are associated with LED module system 100, which are shown in moredetail in FIGS. 7A, 7B, and 8.

According to one embodiment of the invention, the housing/heatsink 252may include an interfacing material which can be used to make contactwith other heat conductive materials, so as to transfer heat from thedevice more easily.

Referring again to FIGS. 5 and 6, cooling fan 260 may be a commerciallyavailable DC fan that is suitably small to be installed withinhousing/heatsink 252 and that provides a cubic feet per minute (CFM) ofairflow that adequate to cool modular LED device 201 when operating. Inone example, cooling fan 260 may be the AFB03505HA fan, supplied byDelta Electronics, Inc. (Fremont, Calif.), which is a 5.50 CFM fan thathas a diameter of 35 millimeters (mm). In another example, cooling fan260 may be the AFB0305MA fan, supplied by Delta Electronics, Inc.(Fremont, Calif.), which is a 3.00 CFM fan that has a diameter of 30millimeters (mm).

Cooling fan 260 is recessed and is, thus, flush with the rear surface ofhousing/heatsink 252 and is secured by a fan guard 262, as shown in FIG.6. In the event that the back of housing/heatsink 252 abuts an obstacle,cooling fan 260 will continue to rotate and draw air from the ends ofhousing/heatsink 252. Cooling fan 260 may be completely temperaturecontrolled via the combination of DSP 112 and temperature sensors 130.Additionally, cooling fan 260 may be turned off in some applications inorder to achieve noise reduction and/or to prolong the lifetime ofcooling fan 260. Fan guard 262 may be formed of any lightweight andrigid material, such as molded plastic, and includes clearances for ACpower port 226, and, for example, two I/O ports 264. AC power port 226may be a standardized receptacle for connecting the AC input voltage(e.g., 110 or 220 VAC) to the power regulator 116. I/O ports 264 may bestandardized receptacles for connecting communications cables for thevarious communication protocols that are described in FIG. 4. Inparticular, the first I/O port 264 may provide an I/O connection to theelectronics of modular LED device 201, whereas the I/O signals may bepassed in a daisy-chain fashion via the second I/O port 264 to anotherinstance of modular LED device 201. In this way, an LED lighting devicemay be formed of a configuration of multiple generic modular LED devices201.

Referring again to FIGS. 5 and 6, modular LED device 201 may be formedof any user-defined array of MIO-LED devices 256 and, thus, itsdimensions may vary accordingly. By way of example, FIGS. 5 and 6illustrate an instance of modular LED device 201 that is formed of a17×5 array of MIO-LED devices 256. In this example, modular LED device201 may have a depth, d, of between 40 and 50 mm (e.g., 44 mm). IfMIO-LED devices 256 are installed on a pitch of, for example, 8.94 mm inthe x-dimension, x-pitch, the resulting overall length, l, of modularLED device 201 may be, for example, 152 mm. If MIO-LED devices 256 areinstalled on a pitch of, for example, 8.55 mm in the y-dimension,y-pitch, the resulting overall height, h, of modular LED device 201 maybe, for example, 42.75 mm.

FIGS. 7A and 7B illustrate a first and second perspective view,respectively, of a PCB assembly 230 for forming LED module system 100 ofthe present invention. PCB assembly 230 includes an arrangement of LEDboard 250 that is mechanically and electrically connected to a drivecontrol board 232, which is mechanically and electrically connected to apower supply (P/S) board 234 and a network interface board 236, uponwhich is installed one or more (e.g., two) I/O connectors 238.

Like LED board 250, drive control board 232, P/S board 234, and networkinterface board 236 may be multi-layer PCBs for implementing theelectronics of LED module system 100 of FIG. 4. In particular, drivecontrol board 232 is the physical instantiation of DSP 112 of LED modulesystem 100, which includes a DSP device and associated circuitry, P/Sboard 234 is the physical instantiation of power regulator 116 of LEDmodule system 100, which includes a compact design of a switch-modepower circuit, and network interface board 236 is the physicalinstantiation of network interface 114 of LED module system 100, whichincludes receiver/driver circuitry that is accessed via I/O connectors238. Network interface board 236 allows up to 512 modular LED devices tobe configured one to another. The mechanical and electrical (e.g.,signal I/O and power) connections between LED board 250, drive controlboard 232, P/S board 234, and network interface board 236 are providedvia standard multi-pin connectors that allow each PCB of PCB assembly230 to be easily connected and disconnected at will.

FIG. 8 illustrates an exploded view of modular LED device 201, whichhouses LED module system 100 of the present invention. In particular,FIG. 8 shows the assembly of LED board 250, drive control board 232, P/Sboard 234, network interface board 236, cooling fan 260, and fan guard262 in relation to housing/heatsink 252. As shown in FIG. 8,housing/heatsink 252 includes clearance regions, in order to accommodateall elements therein. More details of housing/heatsink 252 are providedwith reference to FIGS. 9 and 10.

Additionally, FIG. 8 shows that modular LED device 201 includes amounting plate 238 that abuts the inner side of LED board 250. Mountingplate 238 serves as the mechanical and thermal interface between LEDboard 250 and housing/heatsink 252. The inner surface of LED board 250is coated with a heat spreading material, such as Gap pad VO Ultra soft0.125″ thickness GPVOUS-0.125-AC-0816 from The Bergquist Company(Chanhassen, Minn.), in order to transfer heat that is generated by thecircuitry of LED board 250 to mounting plate 238 and then tohousing/heatsink 252. The combination of LED board 250 and mountingplate 238 is mechanically attached to housing/heatsink 252 viascrews/spacers 254 that are shown in FIG. 5. Mounting plate 238 may beformed of a rigid, lightweight, and thermally conductive material, suchas, but not limited to, aluminum or magnesium. A clearance hole withinmounting plate 238 accommodates the electrical connector between LEDboard 250 and drive control board 232.

The design of modular LED device 201, which includes PCB assembly 230,provides a mechanism by which the electronics may be considered asreplaceable.

More specifically, PCB assembly 230 and, in particular, LED board 250 incombination with mounting plate 238 may be easily removed from the faceof modular LED device 201. Additionally, when LED board 250 incombination with mounting plate 238 is provided as a consumable item,its characterization data and drivers are all inclusive.

FIG. 11 illustrates an exemplary LED configuration 800 of LED modulesystem 100 of the present invention. By way of example, LEDconfiguration 800 shows a 17×5 array of MIO-LEDs devices. The MIO-LEDdevices present in configuration 800 are arranged in rows 1 through 5and in columns A through Q. Additionally, by way of example, theMIO-LEDs devices may be RGW or OCB MIO-LED devices, or a combination ofas described above. In particular, FIG. 11 shows a first quantity of RGWMIO-LED devices (W), a second quantity of RGW MIO-LED devices (W) thatare rotated 180 degrees from its neighbors, a first quantity of OCB(3-in-1) MIO-LED devices (X), a second quantity of OCB MIO-LED devices(X) that are rotated 180 degrees from its neighbors. The presence of OCBMIO-LED devices in combination with RGW MIO-LED devices providesimproved CRI control, as compared with the presence of RGW MIO-LEDdevices only. Additionally, the presence of OCB MIO-LED devices incombination with RGW MIO-LED devices provides improved efficiency,color, and brightness control, as compared with the presence of RGWMIO-LED devices only. Furthermore, alternating the physical orientationof the RGW and OCB MIO-LED devices in relation to their neighborsprovides compensation for differences in the perceived color due todifferences in viewing angles.

Example performance specifications for example configurations are asfollows.

-   16×4 LED configuration of 64 RGW MIO-LEDs: x-pitch=9.5 mm,    y-pitch=10.69, CRI=92%, brightness=800 lm, CT=3200K, power=22 W;-   16×4 LED configuration of 48 RGW and 16 OCB MIO-LEDs: x-pitch=9.5    mm, y-pitch=10.69, CRI=95%, brightness=700 lm, CT=3200K, power=22 W;-   17×5 LED configuration of 85 RGW MIO-LEDs: x-pitch=8.94 mm,    y-pitch=8.55, CRI=92%, brightness=1100 lm, CT=3200K, power=25 W; and-   17×5 LED configuration of 64 RGW and 21 OCB MIO-LEDs: x-pitch=8.94    mm, y-pitch=8.55, CRI=95%, brightness=920 lm, CT=3200K, power=25 W.

FIG. 12 illustrates a flow diagram of a method 900 of operating an LEDmodule system, such as LED module system 100 of the present invention.In particular, the operation of LED module system 100 utilizes thecombination of analog LED drive and digital compensation. Method 900includes, but is not limited to, the following steps.

-   At step 910, DSP 112 of LED module system 100 may receive control    commands from a remote control device via IR sensor 132 and/or an    external controller, such as a computer, via network interface 114.    Method 900 proceeds to step 912.

At step 912, DSP 112 of LED module system 100 may interpret the controlcommands based on a set of predetermined commands for which DSP 112 isprogrammed to recognize. The predetermined commands may relate, forexample, to communications control, on/off control of individual MIO-LEDdevices 120, on/off control of entire LED array 118, cooling systemcontrol, power management control, variable brightness control (i.e.,dimming), variable color control, variable operating efficiency control,and variable CRI control. Method 900 proceeds to step 914.

At step 914, DSP 112 of LED module system 100 may respond to the controlcommands by executing a set of predetermined program instructions foreach respective control command. Method 900 proceeds to steps 916, 918,920, 922, and 924.

At step 916, DSP 112 of LED module system 100 may continuously monitorand control the thermal conditions of modular LED device 201, in orderto provide optimal operation. In particular, DSP 112 may interpretinformation that is received from temperature sensors 130, in order toapply temperature compensation, as needed, to LED circuit 110 that isbased on information, such as light output vs. temperature data, withinstorage device 128. Compensation may be applied to LEDs 118 by DSP 112controlling current sources 122 via DAC 124 and/or DSP 122 controllingPWM switches 126. Method 900 returns to step 910.

At step 918, DSP 112 of LED module system 100 may continuously monitorand control the brightness of modular LED device 201, in order toprovide optimal operation. In particular, DSP 112 may apply brightnesscompensation, as needed, to LED circuit 110 that is based oninformation, such as current vs. color behavior data and light outputvs. temperature data, within storage device 128. Compensation may beapplied to LEDs 118 by DSP 112 controlling current sources 122 via DAC124 and/or DSP 122 controlling PWM switches 126. Method 900 returns tostep 910.

At step 920, DSP 112 of LED module system 100 may continuously monitorand control the color of modular LED device 201, in order to provideoptimal operation. In particular, DSP 112 may apply color compensation,as needed, to LED circuit 110 that is based on information, such ascurrent vs. color behavior data and light output vs. temperature data,within storage device 128. Compensation may be applied to LEDs 118 byDSP 112 controlling current sources 122 via DAC 124 and/or DSP 122controlling PWM switches 126. Method 900 returns to step 910.

At step 922, DSP 112 of LED module system 100 may continuously monitorand control the CRI of modular LED device 201, in order to provideoptimal operation. In particular, DSP 112 may apply CRI compensation, asneeded, to LED circuit 110 that is based on information, such as currentvs. color behavior data and light output vs. temperature data, withinstorage device 128. Compensation may be applied to LEDs 118 by DSP 112controlling current sources 122 via DAC 124 and/or DSP 122 controllingPWM switches 126. Method 900 returns to step 910.

At step 924, DSP 112 of LED module system 100 may continuously monitorand control the CT of modular LED device 201, in order to provideoptimal operation. In particular, DSP 112 may apply compensation, asneeded, to LED circuit 110 that is based on information, such as currentvs. color behavior data and light output vs. temperature data, withinstorage device 128. Compensation may be applied to LEDs 118 by DSP 112controlling current sources 122 via DAC 124 and/or DSP 122 controllingPWM switches 126. Method 900 returns to step 910.

In an alternative circuit arrangement of LED array 118 of LED circuit110 of FIG. 4 that results in increased efficiency, multiple W LEDs maybe driven by a common current source 122, an example of which is shownwith reference to FIG. 13. FIG. 13 illustrates an LED circuit 1000 forincreased efficiency. LED circuit 1000 shows the W (i.e., B+YAG) LEDs ofa plurality of MIO-LED devices electrically connected in series anddriven by a common current source 122. By way of example, FIG. 13 showsfour MIO-LED (3 in 1) devices 1010, wherein the W LEDs are electricallyconnected in series and driven by a common current source 122 andwherein all remaining R and G LEDs are driven by separate current source122. In the arrangement of LED circuit 1000, nine current sources 122are required, rather than twelve as described reference to LED array 118of LED circuit 110 of FIG. 4. The reduced number of current source 122results in increased device efficiency. The scenario of LED circuit 1000provides less color and brightness control as compared with each W LEDhaving its own dedicated current source 122; however, in a staticlighting application brightness uniformity is less critical.Additionally, in this scenario the R LED and G LED, which are drivenindividually, may be used to provide color compensation.

1. A Light Emitting Diode (LED) module lighting system comprising: twoor more multiple-in-one (MIO) LED devices, each MIO-LED devicecomprising at least three LEDs together in a housing body, wherein:light emitting parts of said at least three LEDs are encapsulated in andconnected by a solid, transparent material, and said at least three LEDseach emit a different colour of light, whereby each colour is selectedfrom the group consisting of blue, red, green yellow, orange, cyan,purple, white and magenta; a digital signal processor (DSP); and adigital to analogue converter (DAC) for each LED or a set of LEDs,wherein the system is configured so that signals from the DSP regulatethe overall colour and brightness of light emitted by the MIO-LEDdevices by controlling the power applied to each LED or set of LEDsthrough the DAC.
 2. LED module lighting system according to claim 1,wherein the solid, transparent material comprises at least one phosphormaterial that is activated by light emitted from one or more of saidLEDs, so producing light having a spectrum broader than light emitted bysaid activating LED.
 3. LED module lighting system according to claim 2,wherein the phosphor material comprises one or more of the phosphors oroptical brighteners, wherein the one or more phosphors comprise:ZnS:Ag+(Zn,Cd)S:Ag (P4) (white), Y₂O₂S :Eu+Fe₂O₃ (P22R) (red), ZnS:Cu,AI(P22G) (green), ZnS:Ag+Co-on-AI₂O₃ (P22B) (blue), Zn₂SiO₄:Mn (P1, GJ),(yellowish-green (525 nm)), ZnS:Ag,CI or ZnS:Zn (P11, BE), (blue (460nm)), (KF,MgF₂):Mn (P19, LF) (yellow (590 nm)), (KF, Mg F₂): Mn (P26,LC), (orange (595 nm)), (Zn,Cd)S:Ag or (Zn,Cd)S:Cu (P20, KA),(yellow-green), ZnO:Zn (P24, GE) (green (505 nm)), (Zn,Cd)S:Cu,CI (P28,KE) (yellow), ZnS:Cu or ZnS:Cu,Ag (P31, GH), yellowish-green), MgF₂:Mn(P33, LD) (orange (590 nm)), (Zn,Mg)F₂:Mn (P38, LK), (orange (590 nm))Zn₂SiO₄:Mn,As (P39, GR) (green (525 nm)), ZnS:Ag+(Zn,Cd)S:Cu (P40, GA)(white), Gd₂O₂STb (P43, GY) (yellow-green (545 nm)), Y₂O₂SiTb (P45, WB),(white (545 nm)), Y₂O₂STb, (green (545 nm)), Y₃AI₅O₁₂)Ce (P46, KG)(green (530 nm)), Y₃(AI₁Ga)₅O₁₂)Ce (green (520 nm)), Y₂SiO₅:Ce (P47, BH)(blue (400 nm)), Y₃AI₅O₁₂:Tb (P53, KJ) (yellow-green (544 nm)),Y₃(AIGa)₅O₁₂Tb (yellow-green (544 nm)), ZnSiAg₁AI (P55, BM) (blue (450nm)), InBO₃Tb (yellow-green (550 nm)), InBO₃IEu (yellow (588 nm)),ZnSiAg (blue (450 nm)), ZnSiCu₁AI or ZnSiCu₁AuAI (green (530 nm)),Y₂SiO₅Tb (green (545 nm)), (Zn,Cd)S:Cu,CI+(Zn,Cd)S:Ag,CI (white),lnBO₃Tb+lnBO₃:Eu (amber), (ZnS:Ag+ZnS:Cu+Y₂O₂S:Eu (white),lnBO₃Tb+lnBO₃:Eu+ZnS:Ag (white), (Ba₁Eu)Mg₂AI₁₆O₂₇ (blue),(Ce₁Tb)MgAI₁₁O₁₉ (green), (Y₁Eu)₂O₃ (red), (Sr,Eu,Ba,Ca)₅(PO₄)CI (blue),(La₁Ce₁Tb)PO₄ (green), Y₂O₃IEu (red (611 nm)), LaPO₄ICe₁Tb (green (544nm)), (Sr,Ca,Ba)₁₀(PO₄)₆CI₂:Eu (blue (453 nm)), BaMgAI₁₀O₁₇IEu₁Mn(blue-green (456/514 nm)), (La₁Ce₁Tb)PO₄ICe₁Tb (green (546 nm)),Zn₂SiO₄IMn (green (528 nm)), Zn₂SiO₄IMn₁Sb₂O₃ (green (528 nm)),Ce_(06z)Tb_(0 s3)MgAI₁₁O₁₉ICe₁Tb (green (543 nm)), Y₂O₃IEu(III) (red(611 nm)), Mg₄(F)GeO₆IMn ((red (658 nm)), Mg₄(F)(Ge₁Sn)O₆IMn (red (658nm)), MgWO₄ (pale blue (473 nm)), CaWO₄ (blue (417 nm)), CaWO₄IPb(scheelite, blue (433 nm)), (Ba₁Ti)₂P₂O₇Ti (blue-green (494 nm)),Sr₂P₂O₇ISn, blue (460 nm), Ca₅F(PO₄)₃:Sb (blue (482 nm)),Sr₅F(PO₄)₃:Sb,Mn (blue-green (509 nm)), BaMgAI₁₀O₁₇IEu₁Mn (blue (450nm)), BaMg₂AI₁₆O₂₇IEu(II) (blue (452 nm)), BaMg₂AI₁₆O₂₇IEu(II)₁Mn(II)(blue (450+515 nm)), Sr₅CI(PO₄)₃:Eu(ll) (blue (447 nm)), Sr₆P₅BO₂₀IEu(blue-green (480 nm)), (Ca₁Zn₁Mg)₃(PO₄J₂ISn (orange-pink (610 nm)),(Sr,Mg)₃(PO₄)₂:Sn (orange-pinkish white (626 nm)), CaSiO₃Pb₁Mn(orange-pink (615 nm),) Ca₅F(PO₄)₃:Sb,Mn (yellow), Ca₅(F,CI)(PO₄)₃:Sb,Mn(warm white to cool white or blue or daylight), (Ca₁Sr₁Ba)₃(PO₄J₂CI₂IEu(blue (452 nm)), 3 Sr₃(PO₄)₂.SrF₂:Sb,Mn (blue (502 nm)), Y(P,V)O₄:Eu(orange-red (619 nm)), (Zn,Sr)₃(PO₄)₂:Mn (orange-red (625 nm)), Y₂O₂SiEu(red (626 nm)), (Sr₁Mg)₃(PO₄)_(Z)iSn(II) (orange-red (630 nm)), 3.5MgO.0.5 MgF₂.GeO₂ :Mn (red (655 nm)), Mg₅As₂O₁₁)Mn (red (660 nm)),Ca₃(PO₄)₂.CaF₂:Ce,Mn, (yellow (568 nm)), SrAI₂O₇Pb (ultraviolet (313nm)), BaSi₂O₅)Pb (ultraviolet (355 nm)) SrFB₂O₃:Eu(ll) (ultraviolet (366nm)), SrB₄O₇:Eu (ultraviolet (368 nm)), MgGa₂O₄)Mn(II), (blue-green),(Ce₁Tb)MgAI₁₁O₁₉ (green), Gd₂O₂SiTb (P43) (green (peak at 545 nm)),Gd₂O₂SiEu (red (627 nm)), Gd₂O₂SiPr (green (513 nm)), Gd₂O₂SiPr₁Ce₁F(green (513 nm)), Y₂O₂SiTb (P45) (white (545 nm)), Y₂O₂SiTb (P22R) (red(627 nm)), Y₂O₂SiTb (white (513 nm)), Zn(0.5)Cd(0.4)S:Ag (HS) (green(560 nm)), Zn(0.4)Cd(0.6)S:Ag (HSr) (red (630 nm)), CdWO₄ (blue (475nm)), CaWO₄ (blue (410 nm)), MgWO₄ (white (500 nm)), Y₂SiO₅ICe (P47)(blue (400 nm)), YAI0₃:Ce (YAP) (blue (370 nm)), Y₃AI₅O₁₂ICe (YAG)(green (550 nm)), Y₃(AI₁Ga)₅O₁₂ICe (YGG) (green (530 nm)), CdSiIn (green(525 nm)), ZnOiGa (blue (390 nm)), ZnOiZn (P15) (blue (495 nm)),(Zn₁Cd)SiCu₁AI (P22G) (green (565 nm)), ZnSiCu₁AI₁Au (P22G) (green (540nm)) ZnCdSiAg, Cu (P20) (green (530 nm)), ZnSiAg (P11) (blue (455 nm)),anthracene (blue (447 nm)), plastic (EJ-212, blue (400 nm)), Zn₂SiO₄IMn(P1) (green (530 nm)), ZnSiCu (GS) (green (520 nm)), CsIiTI (green (545nm)), ⁶LiF/ZnS:Ag (ND) (blue (455 nm)), and ⁶LiF/ZnS:Cu,AI,Au (NDg)(green (565 nm)), wherein color of light emitted from each phosphor islisted in parenthesis after the phosphor.
 4. LED module lighting systemaccording to claim 2, wherein: at least one LED in a MIO-LED deviceemits blue light; and phosphor material is yttrium-aluminum-garnet (YAG)phosphor.
 5. LED module lighting system according to claim 1, whereinsaid DSP is configured to control the power applied to each LED or setof LEDs, such that the colour and brightness of light emitted is thesame for each MIO-LED device.
 6. LED module lighting system according toclaim 1, further comprising a pulse width modulator (PWM) switch forcontrolling the power applied to each LED or a set of LEDs, usingsignals from the DSP.
 7. LED module lighting system according to claim6, wherein the DSP is configured to control the PWM switch to adjust thepower supplied to two or more LEDs of the same colour present inseparate MIO-LED devices, when said two or more LEDs emit differentshades of said colour.
 8. An LED module lighting system according toclaim 1, wherein the DSP is configured to control the DAC to adjust thepower supplied to two or more LEDs of the same colour present inseparate MIO-LED devices, when said two or more LEDs emit differentshades of said colour.
 9. An LED module lighting system according toclaim 8, wherein said two or more LEDs of the same colour have not beengrouped by binning.
 10. LED module lighting system according to claim 1,further comprising one or more temperature sensors configured to providetemperature information of the module lighting system to the DSP. 11.LED module lighting system according to claim 10, wherein the DSP isconfigured to control of the power applied to each LED or set of LEDs ofan MIO-LED device based on temperature information received from thetemperature sensors, such that the colour and brightness of lightemitted from each MIO-LED device is maintained where there are changesin temperature.
 12. LED module lighting system according to claim 1,further comprising one or more air cooling fan, configured to cool atleast some of the LEDs.
 13. LED module lighting system according toclaim 12, wherein said DSP is configured to control power to the fanbased on temperature information received from the temperature sensors.14. LED module lighting system according to claim 13, wherein the DSP isconfigured, such that the colour and brightness of light emitted fromeach MIO-LED device is maintained where there are changes intemperature.
 15. LED module lighting system according to claim 1,further comprising one or more network interfaces configured to signalsto the DSP, allowing an external control.
 16. LED module lighting systemaccording to claim 1, further comprising one or more IR sensorsconfigured provide to signals to the DSP, allowing an external control.17. LED module lighting system according to claim 1, further comprisinga power supply configured to supply power to the LEDs and othercomponents.
 18. LED module lighting system according to claim 17,wherein said power supply has a plurality of DC voltage outputs, eachproviding a different voltage to match the rating voltage for acolour-emitting LED.
 19. LED module lighting system according to claim17, wherein said power supply is configured to adapt output level, forat least one colour dependent, on the required light output, controlledby the DSP.
 20. LED module lighting system according to claim 17,further comprising a secondary induction coupler, which provides powerto the power supply by electromagnetic induction from a primaryinduction coupler.
 21. LED module lighting system according to claim 1,further comprising a memory storage device configured to provide data tothe DSP regarding colour and/or brightness compensation information ofeach MIO-LED device.
 22. LED module lighting system according to claim1, wherein the DSP is configured to continuously monitor the powersupplied to each LED in order to maintain the colour and brightnessprovided by each MIO-LED device.
 23. LED module lighting systemaccording to claim 22, wherein the colour and brightness are maintainedaccording to relationships between current and colour behavior, and/orlight output vs. temperature data.
 24. LED module lighting systemaccording to claim 23, wherein said relationships are stored as datawithin storage device where present.
 25. LED module lighting systemaccording to claim 1, wherein the colour temperature, CT, of the emittedlight is adjustable.
 26. LED module lighting system according to claim1, capable of emitting light that provides a high colour renditionindex, CRI.
 27. Modular LED device comprising a housing and one or moreLED module systems according to claim 1, whereby: an array of MIO-LEDdevices is arranged as a light emitting surface, and a mechanical meansto stack two or more modular LED devices is provided.
 28. Modular LEDdevice according to claim 27, whereby said mechanical stacking meansaligns the respective light emitting surfaces to project light towardsthe same direction.
 29. Modular LED device according to claim 28,wherein the housing comprises an interfacing material which can be usedto make contact with other heat conductive materials, so as to transferheat from the device more easily.